docs: def _get_current_albedo(self):
          '''Simple step-function albedo based on ice line at temperature Tf.'''
          ice = self.subprocess['iceline'].ice
          # noice = self.subprocess['iceline'].diagnostics['noice']
          cold_albedo = self.subprocess['cold_albedo'].albedo
          warm_albedo = self.subprocess['warm_albedo'].albedo
          albedo = Field(np.where(ice, cold_albedo, warm_albedo), domain=self.domains['Ts'])
          return albedo